防冲专项专项措施必须在()半个月完成。
参考答案:开工前
It was Alice and her friends who helped the homeless old woman,______?
A.wasn’t it?
B.wasn’t she
C.didn’t they?
D.weren’t they?
What is a cofferdam().
A.Tube fitted to an ullage hole
B.Area the product is loaded into
C.Void or empty space separating two tanks
D.Opening in the deck used for cleaning a tank